The present invention relates to a process for the visual display of the attitude of an aircraft in order to assist flying or piloting in space. It more particularly applies to the ergonomic display and the attitude display of an aircraft in space, as well as the display of values for the angular displacement velocities thereof. It also applies to the simultaneous display of the position of another object such as a space satellite travelling in the surrounding space.
It is not presently known how it is possible to precisely and ergonomically display the attitude of an aircraft and more particularly that of a space vehicle, such as a shuttle. All that is known in connection with aeroplanes consists of processes involving the use of electromechanical devices called "spheres" or display screen devices, enabling the pilot to know the attitude of the aircraft in a restricted space area representing only a few degrees relative to the horizon.
Thus, the attitude of an aircraft is generally indicated by the values of the three cardan or gimbal angles, namely role (.phi.), pitch (.theta.) and yaw (.psi.) defined in a reference mark. This attitude represented in a mark linked with the aircraft loses all accuracy when the pitch angle is close to .+-.90.degree.. For example, when a fighter rockets, the information supplied by the "aircraft sphere" are incoherent as a result of sphere oscillations. This information is also incoherent close to the poles (in the vicinity of the poles, .theta. is close to .+-.90.degree.).
Processes using visual display devices coupled with electronic attitude measuring systems generally have no better performance characteristics than those using the "aircraft sphere". They only give imprecise information on the aircraft attitude, as soon as the pitch angle exceeds 80.degree., or when the aircraft is travelling close to the poles.
These disadvantages of existing processes used on aircraft become major inconveniences for assisting the flying of a spacecraft.